// 数据类型
/*
* 基本数据类型: string number boolean null undefined symbol
* 引用数据类型: object function array
* 
* */

// 值传递
let a = 3;
let b = a;
b = 4;
console.log(a);
// 引用传递
let c = {username: 'kobe'}
let d = c;
d.username = 'curry'
console.log(c);

// 面试题
let f = 2;
let h = 3;
// 不借助任何其他变量交换f, h值
f = f + h;
h = f - h;
f = f - h;
console.log(f, h);

